Installations of car body welding assembly systems in accordance with prior U.S. Pat. Nos. 4,162,387 and 4,256,947 have generally employed two or three sets of interchangeable gates in reciprocable relation at a single framing station.
One or more additional framing stations have been employed, on occasion in parallel feeding into a common respot welding line, where a variety of body styles requiring more than three sets of gates has been involved. Duplication of programmable welding robots at each framing station has accordingly multiplied the framing station cost, even where production capacity requirements could be satisfied by a single framing station if it were capable of accommodating the additional different body styles.